rshift.asm
上传用户:qaz666999
上传日期:2022-08-06
资源大小:2570k
文件大小:2k
- dnl IBM POWER mpn_rshift -- Shift a number right.
- dnl Copyright 1992, 1994, 1999, 2000, 2001 Free Software Foundation, Inc.
- dnl This file is part of the GNU MP Library.
- dnl The GNU MP Library is free software; you can redistribute it and/or modify
- dnl it under the terms of the GNU Lesser General Public License as published
- dnl by the Free Software Foundation; either version 3 of the License, or (at
- dnl your option) any later version.
- dnl The GNU MP Library is distributed in the hope that it will be useful, but
- dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
- dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
- dnl License for more details.
- dnl You should have received a copy of the GNU Lesser General Public License
- dnl along with the GNU MP Library. If not, see http://www.gnu.org/licenses/.
- dnl INPUT PARAMETERS
- dnl res_ptr r3
- dnl s_ptr r4
- dnl size r5
- dnl cnt r6
- include(`../config.m4')
- ASM_START()
- PROLOGUE(mpn_rshift)
- sfi 8,6,32
- mtctr 5 C put limb count in CTR loop register
- l 0,0(4) C read least significant limb
- ai 9,3,-4 C adjust res_ptr since it's offset in the stu:s
- sle 3,0,8 C compute carry limb, and init MQ register
- bdz Lend2 C if just one limb, skip loop
- lu 0,4(4) C read 2:nd least significant limb
- sleq 7,0,8 C compute least significant limb of result
- bdz Lend C if just two limb, skip loop
- Loop: lu 0,4(4) C load next higher limb
- stu 7,4(9) C store previous result during read latency
- sleq 7,0,8 C compute result limb
- bdn Loop C loop back until CTR is zero
- Lend: stu 7,4(9) C store 2:nd most significant limb
- Lend2: sre 7,0,6 C compute most significant limb
- st 7,4(9) C store it
- br
- EPILOGUE(mpn_rshift)